The use of slurry ice, both alone and in combination with ozone, as compared with
traditional flake ice was investigated as a new refrigeration system for the storage
of sardine (Sardina pilchardus). Microbiological, chemical and sensory analyses were
carried out throughout a storage period of 22 days. According to sensory analyses,
sardine specimens stored in ozonised slurry ice had a shelf life of 19 days, while
counterpart batches stored in slurry ice or flake ice had shelf lives of 15 and 8
days, respectively. Storage in ozonised slurry ice led to significantly lower counts
of aerobic mesophiles, psychrotrophic bacteria, anaerobes, coliforms, and both lipolytic
and proteolytic microorganisms in sardine muscle, and of surface counts of mesophiles
and psychrotrophic bacteria in sardine skin as compared with the slurry ice and the
flake ice batches. In all cases, the slurry ice batch also exhibited significantly
lower microbial counts, both in muscle and skin, than the flake ice batch. Chemical
parameters revealed that the use of slurry ice slowed down the formation of TVB-N
and TMA-N to a significant extent in comparison with storage in flake ice. A combination
of slurry ice with ozone also allowed a better control of pH and TMA-N formation as
compared with slurry ice alone. This work demonstrates that the combined use of slurry
ice and ozone for the storage of sardine can be recommended to improve the quality
and extend the shelf life of this fish species.